Manufacture of incandescing carbon filaments



(No Model.) 4 E. P. THOMPSON.

MANUFACTURE OF INGANDESGING CARBON FILAMENTS.

No. 401,607 Patented Apr.. 16, 1889.v

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UNITED STATES ATENT rric EDWARD P. THOMPSON, OF ELIZABETH, NEW JERSEY.

MANUFACTURE OF INCANDESCING CARBON FILAMENTS.

SPECIFICATION forming part of Letters Patent No 401,607, dated April 16, 1889. Application filed March 28, 1887. Sen'al No. 232,785. (No model.)

To all whom it may concern: The invention will be described in detail Be it known that I, EDWARD P. THOMPSON, in connection with the accompanying drawacitizen of the United States, residingin Elizaings, in which Figure 1 illustrates an appabeth, in the county of Union and State of New ratus for receiving and drying the filaments Jersey, have invented certain new and useful after they have been partially carbonized by Improvements in Process of Oarbonizing Filthe acid solution. This same apparatus or an aments for Incandescent Electric Lamps, of equivalent chamber may be employed for which the following is a specification. treating the filaments with a solution of liq- The invention relates to a method of preuid hydrocarbon for replacing the oxygen. paring filaments for incandescent electric Fig. 2 illustrates the apparatus employed for lamps, in which the fiber is first partially carfinally carbonizing the filaments. bonized by being treated by acids and subse- Referring to the figures, A represents a suitquently completely carb nized by heat. able chamber, which is preferably air-tight, The object of the invention is to provide and in which there are placed molds B, upon means for expelling all the oxygen which may which the partially-carbonized filaments are be absorbed by the filaments and by the molds placed. This chamber is provided with a carrying them after the filaments are partially pipe, 0, through which steam or hot air is carbonized by acids and before they are subpassed for the purpose, in the first instance, jected to heat for completing the carbonizaof heating the filaments and the molds, thereby tion. drying and stiffening the former before they The invention consists, in general terms, in are carbonized by heat. At a suitable point an first subjecting the filaments toan acid bath outlet, at, provided with a stop-cock, a, leads after the process described in United States from the chamber A. The vapors arising Patent N o. 323,32, dated July 28, 1885, in from the heating of the chamber may escape which the filaments are placed in an aciduthrough an outlet, a which at other times may be closed by a valve, a

lated saccharine solutionsuch, for instance, as sulphuric acid containing sugar in solution. preferably constructed after the manner of a safety-valve, but is held open during the pro- After the filaments are removed from this bath they are dried, and being partially carcess of drying and stiifening the filaments.

After the filaments have been heated the bonized the pores absorb more or less oxygen. It is desired by the present invention to rechamber is partially filled with a hydrocarbon liquid through the opening a or in any other move such oxygen from the filaments before they are completely carbonized by heat. The convenient manner, and heat is again applied filaments are placed upon suitable forms, prefthrough the pipe 0. The heat serves to vaerably molds of carbon blocks, before they porize a portion of the hydrocarbon, and, the valve a being closed, a greater or less pressare placed in a heating-oven. These blocks are more or less porous, and naturally contain ure will be exerted upon the liquid hydrocarbon, forcing it to enter the pores of the filaa greater or less quantity of oxygen. The present invention involves the expelling of ments and the molds, thus driving out the oxygen and replacing it with hydrocarbon.

this oxygen also before the molds and the filaments are placed in the carbonizing-oven. After this treatment the molds, with the fila- For this purpose they are placed in a suitable ments carried thereby, are placed in a suitchamber and immersed in a hydrocarbon liqable crucible of fire-clay, nickel, or other suitable material, as shown in Fig. 2 at D. The

uid, which is then placed under pressure,

thereby forcing the liquid into the pores and molds are covered and surrounded by powreplacing the oxygen. The molds and filadered carbon and the crucible is tightly closed ments are then subjected to the carbonizing at the top by' a cover, CZ, cemented or tightly closed and sealed in any other convenient process in the usual manner, and as practically all the oxygen has been expelled theremanner. A tube, d, leads to a condenser, E, of any suitable character for receiving the from the filaments are not injured by being themselves attacked by the oxygen. vapors which come from the hydrocarbon with lamps, Which consists in Winding the filaments upon carbon blocks, displacing the occluded 1o gases in the blocks and filaments, filling the pores of the blocks and filaments with an inert fluid, and carbonizing the filaments.

In testimony whereof I have hereunto subscribed my name this 24th day of March, A. D. 1887 EDWARD P. THOMPSON.

Vitnesses:

DANL. W. EDGECOMB, CHARLES A. TERRY. 

